This application claims benefit of priority under 35 USC xc2xa7119 to Japanese Patent Application No. P2001-067387, filed on Mar. 9, 2001, the entire contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to printing machines having a plurality of printing sections and printing methods. More particularly, the invention relates to a printing machine and a printing method being easy to discriminate a specific printing section, which has executed the printing of a particular print sheet.
2. Description of the Related Art
In the related art, extensive attempts have heretofore been undertaken to provide printing machines, such as ink jet printers, thermal head printers and stencil printing machines, which allow a print sheet to be reproduced with notes and image data prepared by personal computer. These printing machines are devised in various ways so as to maintain a reproduced image at a high quality.
For example, in a serial printer arranged to perform bi-lateral printing by shifting a print head in the main scanning direction, the presence of bi-lateral printing operations carried out over a long time causes a shear in the printing position with respect to a main scanning direction, due to a backlash of the drive mechanism of a print head occurring in the main scanning direction or an imbalance occurring in a drive mechanism owing to stretching of a carriage belt.
Generally such a shear in the printing position is corrected by adjusting the alignment of the print cartridge.
When adjusting the alignment of the print cartridge, as shown in FIG. 1, a plurality of (for example, thirty) vertical rule marks, as indicated by a set of lines xe2x80x9caxe2x80x9d, are initially printed on a print sheet at an equal interval by shifting a print head from left to right in the main scanning direction.
Then, a plurality of vertical rule marks, as indicated by a set of lines xe2x80x9cbxe2x80x9d, are printed on the print sheet by shifting the print head from right to left in the main scanning direction, so that the amounts of displacement of the vertical rule marks xe2x80x9cbxe2x80x9d with respect to the previously printed vertical rule marks xe2x80x9caxe2x80x9d gradually change (i.e. increase or decrease) at a predetermined rate.
Finally, the vertical rule marks, as indicated by a set of lines xe2x80x9ccxe2x80x9d, are printed in the same manner as the vertical rule marks xe2x80x9caxe2x80x9d.
These printed matters as shown in FIG. 1 are referred to as test patterns, which have reproduced the print cartridge adjustment data (that corresponds to alignment adjustment data for the print head).
Among these test patterns, the number of the test pattern, wherein particular the vertical rule marks along a vertical line are closest to a straight line is selected and is stored in particular section of the serial printer as an adjustment value to a control section via an operation panel mounted on a body of the serial printer or a printer driver installed in the computer connected to a serial printer. Then, based on the adjustment value the shear in the printing position is corrected by controlling the print head.
For example, since number xe2x80x9c16xe2x80x9d of the test patterns wherein the shear of the respective vertical rule marks in printing among the sets of lines a, b, c remains at a minimum value as shown in FIG. 1, number xe2x80x9c16xe2x80x9d as a adjustment value is inputted to a control section via an operation panel mounted on a body of the printing machine or a printer driver installed in the computer, and stored in a predetermined section of the serial printer. Then, based on the adjustment value the shear in the printing position is corrected by controlling the print head
In addition, print cartridge adjustment data may also involve data for executing the cleaning of an election nozzles.
During such an adjustment process of the print cartridge, in a case where the test patterns are outputted from a printing machine equipped with one set of a printing section, it is easily to judge which printer outputted the test patterns.
However, with a printing machine equipped with a plurality of printing sections, once the test patterns have been printed on the print sheets it becomes difficult to judge the correspondence between the printing section which printed the test patterns and its test patterns.
Further, there are some instances where the use of plural printing sections to execute printing operations on a large number of print sheets causes print sheets of a deteriorated print quality to be produced. In such instances, it is not easy to judge which printing section has outputted the print sheets of a deteriorated print quality.
The present invention has been made with the above in mind and has an object of providing technology wherein identification marks corresponding to respective printing sections are printed on print sheets when printed by the respective printing sections, respectively, thereby providing ease of judgment of the corresponding relationship between the printing sections and the print sheets correlated therewith.
To achieve the above object, an aspect of the present invention inheres in a printing machine encompassing a housing; a plurality of printing sections mounted in the housing configured to execute a printing operation on the basis of given data; a control section configured to allow the respective printing sections to print on print sheets on the basis of print data while controlling the respective printing sections to allow print identification marks to be printed on the print sheets on the basis of identification mark data representing the printing section; and a sheet discharge section configured to allow printed sheets outputted in respective printing sections to be stacked.
Another aspect of the present invention inheres in a method of printing embracing the steps of printing on print sheets at a plurality of printing sections on the basis of print data; printing identification marks on the print sheets on the basis of identification mark data representing which printing section has been operated to execute printing; and placing the print sheets, which has been printed and outputted at the respective printing sections, in a stack in a sheet discharge section.
Still another aspect of the present invention inheres in a method of printing embracing the steps of inputting print data and identification mark data representing which printing section has been operated to execute printing into a printing machine; allocating the print data and the identification mark data to corresponding printing sections, respectively; printing on print sheets, transferred to a plurality of printing sections, on the basis of the print data while printing identification marks on the print sheets on the basis of identification mark data; and placing the print sheets, which have been printed and outputted at the respective printing sections, in a stack in a sheet discharge section.
Other and further objects and features of the present invention will become obvious upon an understanding of the illustrative embodiments about to be described in connection with the accompanying drawings or will be indicated in the appended claims, and various advantages not referred to herein will occur to one skilled in the art upon employing the present invention in practice.